Flexible Turbine Coupling Shaft for Torque Change Compensation
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Solution Overview
Problem
Gas turbine engines face challenges in increasing efficiency, reducing fuel consumption, and minimizing noise while maintaining or decreasing packaging dimensions, particularly due to intermittent torque changes and torque paths that can lead to deformations and overspeed conditions.
Innovation Solution
A flexible shaft assembly with a coupling system that includes axially and radially extended splines and platforms for interference fit, separating torque and speed sensing paths, and positioning torque and speed sensors to minimize critical path interference, allowing for deformation compensation and reduced packaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a reduction gearbox is introduced between engine core and fan/propeller to increase efficiency, then turbine engine efficiency is improved, but turbine engine packaging increases
Solution Approach 1:
The flexible shaft is configured to extend primarily in the radial direction rather than axially, allowing the gearbox to be positioned closer to the engine core in the radial dimension. This dimensional reorganization reduces the axial length required for the torque transmission path, thereby reducing overall engine packaging while maintaining the efficiency benefits of the reduction gearbox.
Solution Approach 2:
The flexible shaft is positioned to extend through or alongside existing engine core structures, nesting the torque transmission path within the existing engine architecture. This allows the gearbox to be integrated more compactly into the engine assembly without requiring additional external space.
2Stability of the object's composition
If a rigid shaft is used to connect engine core and gearbox, then torque transmission is stable, but the system cannot compensate for intermittent torque changes and deformations
Solution Approach 1:
The shaft is designed with flexible elements including splines that can move relative to each other, allowing the shaft to dynamically adapt to changing torque conditions. The splined connection enables controlled deformation and movement in response to intermittent torque changes from the engine core, preventing stress concentration and potential failure while maintaining reliable torque transmission.
Solution Approach 2:
The flexible shaft design allows for changes in geometric parameters such as spline position and shaft curvature in response to varying torque loads. This parameter adaptability enables the shaft to compensate for deformations and maintain stable torque transmission under varying operating conditions.
3Device complexity
If torque and speed sensing paths are integrated, then system complexity is reduced, but response time to overspeed conditions is delayed
Solution Approach 1:
The sensing system is segmented into separate torque sensing and speed sensing paths, with each sensor positioned at optimal locations along the torque transmission path. This segmentation allows each sensing function to operate independently and report to the control system, enabling faster detection and response to overspeed conditions without requiring complex integrated sensing mechanisms.
Data Source
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AI summary
The present disclosure is directed to a shaft assembly for a turbine engine, wherein the turbine engine includes a fan or propeller assembly (14) and an engine core (20), and further wherein the fan or propeller assembly includes a gearbox (45), and wherein the engine core includes one or more rotors. The shaft assembly includes a flexible shaft (100) defining a first end and a second end along the axial direction, wherein the first end is connected to the engine core and the second end is connected to the gearbox, and wherein a plurality of splines is defined at the second end and coupled to a spline interface at the gearbox; and a coupling extended at least partially in the radial direction and coupled to the engine core and the flexible shaft.